Contemporary role of modern brachytherapy techniques in the management of malignant thoracic tumors

Long-term results of curative intraluminal high dose rate brachytherapy for endobronchial carcinoma

BACKGROUND

The treatment strategy of central lung tumors is not established. Intraluminal brachytherapy (ILBT) is widely used for palliative treatment of endobronchial tumors, however, it is also a promising option for curative treatment with limited data. This study evaluates the results after ILBT for endobronchial carcinoma.

METHOD

Sixteen-endobronchial carcinoma of 13 patients treated with ILBT in curative intent for 2000 to 2008 were retrospectively reviewed. ILBT using high dose rate 192 iridium thin wire system was performed with 5 Gy/fraction at mucosal surface. The patient age ranged from 57 to 82 years old with median 75 years old. The 16 lesions consisted of 13 central endobronchial cancers including 7 roentgenographically occult lung cancers and 3 of tracheal cancers. Of them, 10 lesions were treated with ILBT of median 20 Gy combined with external beam radiation therapy of median 45 Gy and 6 lesions were treated with ILBT alone of median 25 Gy.

RESULTS

Median follow-up time was 32.5 months. Two-year survival rate and local control rate were 92.3% and 86.2%, respectively. Local recurrences were observed in 2 lesions. Three patients died due to lung cancer (1 patient) and intercurrent disease (2 patients). Complications greater than grade 2 were not observed except for one grade 3 dyspnea.

CONCLUSIONS

ILBT combined with or without EBRT might be a curative treatment option in inoperable endobronchial carcinoma patients with tolerable complication.

Clinicopathologic Comparison of High-Dose-Rate Endorectal Brachytherapy versus Conventional Chemoradiotherapy in the Neoadjuvant Setting for Resectable Stages II and III Low Rectal Cancer

Purpose. To assess for differences in clinical, radiologic, and pathologic outcomes between patients with stage II-III rectal adenocarcinoma treated neoadjuvantly with conventional external beam radiotherapy (3D conformal radiotherapy (3DRT) or intensity-modulated radiotherapy (IMRT)) versus high-dose-rate endorectal brachytherapy (EBT). Methods. Patients undergoing neoadjuvant EBT received 4 consecutive daily 6.5 Gy fractions without chemotherapy, while those undergoing 3DRT or IMRT received 28 daily 1.8 Gy fractions with concurrent 5-fluorouracil. Data was collected prospectively for 7 EBT patients and retrospectively for 25 historical 3DRT/IMRT controls. Results. Time to surgery was less for EBT compared to 3DRT and IMRT (P < 0.001). There was a trend towards higher rate of pathologic CR for EBT (P = 0.06). Rates of margin and lymph node positivity at resection were similar for all groups. Acute toxicity was less for EBT compared to 3DRT and IMRT (P = 0.025). Overall and progression-free survival were noninferior for EBT. On MRI, EBT achieved similar complete response rate and reduction in tumor volume as 3DRT and IMRT. Histopathologic comparison showed that EBT resulted in more localized treatment effects and fewer serosal adhesions. Conclusions. EBT offers several practical benefits over conventional radiotherapy techniques and appears to be at least as effective against low rectal cancer as measured by short-term outcomes.

Severe toxicity after permanent radioactive seed implantation for mediastinal carcinoid tumors

PURPOSE

Permanent implantation of 125I seeds may be used when uninvolved surgical margins are unobtainable or close. Two cases of mediastinal carcinoid tumors with prior chemoradiation had tumors adherent to esophageal muscularis. Both underwent intraoperative permanent seed implantation and developed esophageal fistulas requiring surgical correction.

METHODS AND MATERIALS

Custom permanent 125I seed mesh implants were fashioned intraoperatively in a geometrically coherent pattern. The implants were directly sutured to the partially resected esophageal wall. The postimplant CT scans were fused with the postfistula scans to provide dosimetric information at the fistula site. Doses were calculated from time of insertion to time of fistula formation. Neither patient showed evidence of disease recurrence at the time of fistula repair.

RESULTS

Patient 1 developed an esophageal-pleural fistula 83 days after seed implantation. Patient 2 developed a broncho-pleural fistula 300 days after seed implantation.

CONCLUSIONS

These cases demonstrated that implantation in the setting of extensive subcarinal space dissection and partial esophageal wall resection could cause fistula formation and the need for additional surgery. The high mucosal dose, despite the relatively low activity implant, was due to lack of geometric sparing of the mucosa. We recommend that extensive subcarinal space dissection be considered a contraindication to permanent seed implantation.

Uncommon Primary Tracheal Tumors

BACKGROUND

Primary tracheal tumors other than adenoid cystic or squamous cell carcinoma are uncommon and have a heterogeneous histologic appearance. The experience regarding their treatment and long-term outcome is limited, and alternatives to segmental tracheal resection, including endoscopic treatment or radiation, continue to be explored.

METHODS

A retrospective analysis was performed of uncommon tracheal tumors among 360 primary tracheal tumors seen over 40 years, excluding adenoid cystic and squamous cell carcinoma.

RESULTS

Of 90 patients, 34 (38%) had benign tumors and 56 malignant: 11 carcinoid tumors, 14 mucoepidermoid carcinomas, 13 sarcomas, 15 nonsquamous bronchogenic carcinomas, 2 lymphomas, and 1 melanoma. Three patients had a second tracheal malignancy. Dyspnea was the most common symptom in benign tumors and hemoptysis in malignant tumors. Twelve patients did not undergo tracheal resection (13.3%) and 1 died before resection. Surgical therapy in 77 patients (85%) consisted of laryngectomy in 3, laryngotracheal resection in 9, tracheal resection in 46, and carinal resection in 19. Hospital mortality was 2.6% (2 of 77 patients) and major complications occurred in 16% (12 of 77 patients). Mean follow-up was 9.7 years. After resection, survival at 10 years was 94% for benign and 83% for carcinoid tumors, and at 5 years survival was 60% for bronchogenic carcinoma, 100% for mucoepidermoid tumors, and 78% for sarcomas. Patients with lymphomas and melanoma are alive more than 8 years after resection. Ten patients experienced recurrence (14%).

CONCLUSIONS

Surgical resection of uncommon primary tracheal tumors alleviates airway obstruction, is curative in patients with benign or slow-growing malignant lesions, and prolongs survival in highly malignant lesions.

Primary tracheal tumors

Primary tracheal tumors often present with locally advanced tumors. A majority of patients can safely undergo tracheal, laryngotracheal, or carinal resection with low perioperative risk. Airway interventions at the time of diagnosis should be selected carefully to avoid a compromise of curative treatment. Precise judgment is required to determine resectability. The proximity of intrathoracic organs creates anatomical limits to en bloc resection and necessitates adjuvant radiotherapy in malignant tumors. Early referral for consideration of surgical resection might offer the best opportunity for improving the overall prognosis of tracheal tumors.